Apparatus for promoting the vigilance of a motor vehicle operator

ABSTRACT

A device for maintaining the vigilance of a motor vehicle operator. Two preferred embodiments, maintaining the operator&#39;s attention toward the direction of developing traffic conditions, with a visual system focused at infinity, are disclosed. One shows an image which is projected or otherwise transmitted from below the normal line of sight of the operator, while the other illustrates transmission of the image from above the vehicle operator. The invention overcomes &#34;road hypnosis&#34; or other inattentiveness by maintaining the operators&#39;s interest, thereby putting the operators&#39;s psychological perceptive apparatus in a high state of readiness.

FIELD OF THE INVENTION

This invention relates to motor vehicle safety systems and moreparticularly to an apparatus to attract the visual attention of a motorvehicle operator generally toward the direction of travel.

BACKGROUND INFORMATION

Operating a motor vehicle is a complicated task, demanding the use ofvisual and physical skills combined with the ability to make judgmentsrapidly. Quite clearly, a certain minimal level of physical skills isrequired to drive successfully. In most of the United States, this factis recognized in that to receive a license, motor vehicle operators mustfirst pass a vision test and then demonstrate these visual and physicalskills in a driving test. On-the-road tests also force the person testedto demonstrate skills of judgment.

There are, however, certain skills or abilities that such tests simplydo not measure. Among these is the ability of an operator to maintainvigilance with regard to ever-changing driving conditions.

Failure of operator vigilance frequently occurs during long highwaytrips and during shorter, more local, trips where the operator has cometo expect certain driving conditions and driver behaviors. In bothcases, this diminished attentiveness impairs the ability of the operatorto react adequately to these changing conditions and may result in atraffic accident.

The importance of this problem has not been overlooked. A variety ofapproaches to monitoring and maintaining driver alertness have beendeveloped. Among these is a class of devices which monitor steeringwheel motions. When the pattern of steering wheel motions shows that thedriver's attention level has gone below that considered to be safe, analarm for regaining the attention of the driver is activated. Of course,the recent advent of high-mounted stoplights also has the purpose ofattracting and maintaining the attention of drivers following a vehiclewhich is so equipped.

Driving a motor vehicle is a task which demands relatively more visualthan auditory attention. This explains why a person can successfullydrive an automobile and simultaneously listen to a radio program. Anyevents that divert a driver's visual attention from the outsidesurroundings ahead of the vehicle immediately increase the probabilityof the vehicle being involved in a mishap. An example of such an eventis to encounter two vehicles that have collided, parked by the side ofthe road. The peripheral accidents that occur at such sites evidence theincreased chances of being involved in a collision when an operator'sattention is visually distracted.

As noted in "Hidden Visual Processes," Scientific American, February1983, p. 97, Drs. Herschel Leibowitz and D. Alfred Owens found that ahuman being, when deprived of any visual stimuli, will resort to acondition known as "dark focus." In this condition, the subject's visualsystem assumes a focal distance of approximately one meter. The "darkfocus" phenomenon is believed to be an explanation for so-called "roadhypnosis" experienced by many long distance drivers. To bring a personout of a state of "road hypnosis," it is necessary first to gain theattention of the individual, and then to give the person enough time torefocus visual attention. Under the circumstances, there may not beenough time to respond to an emergency.

Dr. Richard Restak reports on page 29 of "The Brain: The Last Frontier",Doubleday & Co., 1979, that experiments suggest that primates derivepleasure from observing complex situations involving color, brightness,and movement. Rhesus monkeys, when given the means, will create moviesin preference to still photographs. Modern psychobiological research isshowing that a human's response is strongly affected by and may even bedependent upon movement in the environment. This movement creates thenovelty and stimulation, implying the greater information content, whichprimates seem to desire. To keep a vehicle operator stimulated to thepoint of maximal responsiveness, then, it is advantageous to present amoving visual image in the general direction requiring the greatestattention.

Further recent phychobiological research has been directed towardevoked-responses. These evoked response studies show that, as measuredby a brain response which is known as the P300 wave, a human subject'sinterest is maintained at its highest state when unpredictableinformation is presented to the subject is presented with newinformation; the lack of new information brings about a diminishedresponse of the P300 wave. One current theory relating to the P300 waveis that the existence of a P300 wave represents a decision-makingactivity within the cortex of the brain. A possible application of thispsychological research of the P300 wave is to support the theory thataggressive people may be influenced to drive more safely through itsuse. The rationale for this theory is that aggressive behavior is oftenthe result of an attempt by the vehicle operator to stimulate the evokedresponses indicated by the P300 wave.

A driver whose visual system is already properly focused severalcarlengths ahead will obviously not have to refocus in order to respondto an emergency. As an aid to maintaining a properly focused visualsystem, the driver should be attracted to something at that distance.

Many persons have "watched" television, enjoying the program byoccasionally looking at the television screen, while simultaneouslyperforming another, primarily visual task, such as reading a newspaper.This is apparently possible because audio-visual programs typically relyprimarily upon auditory channels to transfer information. The visualchannels are used only for occasionally updating or confirmingsituations, or resolving ambiguities. In other words, an individual mayenjoy an audio-visual program while spending only a small fraction ofthe time actually looking at it.

Since the time that they were first used in automobiles, radio receivershave served the dual purposes of providing entertainment and helping tomaintain driver alertness. These purposes are served on long-distancetrips as well as shorter commuter trips, where the tedium of congestedtraffic conditions can lead to driver inattentiveness. The recentintroduction of audio cassette players to motor vehicles has given thedriver an additional method of entertainment and maintaining alertness.It is quite clear that a significant degree of driver attention may besustained solely through the human auditory system.

The experience of pilots flying aircraft equipped with head-up displayshas shown that the ability of a properly trained pilot to fly anaircraft is not diminished when the pilot concurrently assimilatesinformation presented by the head-up display. An important aspect ofthis phenomenon is that the pilot need not refocus when divertingattention from one task to another. This is true even though the fieldsof information may coincide with each other.

The apparatus for maintaining vigilance by attracting an operator'svisual attention ahead of the vehicle with a head-up visual display andentertainment system whose images are focused at infinity will promotehighway safety. When using such a system, the individual's focus ofattention can alternate between a view of the road ahead and a displayof visual information while improving driving performance.

SUMMARY OF THE INVENTION

The present invention is broadly directed toward the use of a head-updisplay for presenting the visual component of an audio-visualentertainment or education program to the operator of a motor vehicle.The visual images are focused at an infinite distance enabling theoperator's visual system to react quickly to developing trafficconditions. With this system, the operator need not divert attentionfrom the view ahead to read instrumentation within the vehicle. Mostimportant, however, is the fact that the attention of an operator usingsuch a system is far more likely to be directed ahead of the vehicle.

As disclosed in both of the following detailed descriptions of preferredembodiments, the visual display appears slightly above the angular levelat which traffic conditions appear. Only a slight angular deviation isrequired to redirect the driver's attention from the visual display tothe driving situation, and back. The display is transmitted to thisposition through any of a variety of transmissive means, includingdirect projection of the image and electronic transfer to a read-outdevice.

The source of this entertainment/education programming can be, amongother things, broadcast television signals or prerecorded videocassettes being replayed on a video cassette player. The image may alsocontain relevant instrument readings or navigational information, suchas maps.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the driver vigilance apparatus built inaccordance with the present invention are disclosed in the followingdetailed descriptions. The descriptions make reference to theaccompanying drawings in which:

FIG. 1 is a schematic drawing of a first embodiment of the apparatus ofthe present invention; and

FIG. 2 is a schematic drawing of a second embodiment of the apparatus ofthe present invention.

DETAILED DESCRIPTIONS OF THE PREFERRED EMBODIMENTS

Referring now to FIG. 1 of the drawings, one preferred embodiment of thepresent invention can be appreciated. FIG. 1 shows a schematic drawingof a motor vehicle having a forward body panel 12, a relativelytransparent windshield 14 made of glass, plastic or some substitutablematerial, and a steering wheel 16. The steering wheel is attached to asteering column 18 which passes forward through the dash panel 20.

The operator's eyes 22 are located at some relatively unchangingposition with respect to the automobile components just mentioned. Theview of the driving conditions ahead of the vehicle are presented to theoperator's eyes 22 by means of light rays 24, which are shown cast at aslight downward angle toward the pavement upon which the automobile isdriving. The light rays 24 comprising the scene ahead of the vehiclepass through the windshield 14 virtually undistorted. A region 26 of theinner surface of windshield 14 is specially treated to act as areflecting surface for light energy coming from below the inner surfaceof the windshield 14. For example, a dichroic mirror could be formed inregion 26, placed so as to allow light energy striking region 26 frombelow to be reflected toward the operator's eyes 22, while transmitting,to eyes 22, the light rays which carry the information constituting thescene ahead of the vehicle.

It is clear then, that light rays 34 result from reflections of lightenergy from the inner surface 26 of windshield 14. The light rays 34 arecollimated, presenting an image which appears to be approximately visualinfinity. The image represented by rays 34 is produced by the reflectionof the rays 36. These rays, in turn, result from collimation bycollimator 37 of the light energy which emanates from a video displaysource 38, such as a cathode ray tube (CRT). The image is displayed onthe front face of video display source 38, in accordance with signalssent to it by signal source 40. Signals produced by source 40 are passedto video display source 38 by means of a cable 42. Source 40 can be ofany of a variety of devices. Chief among the choices are a televisionreceiver with a receiving antenna, a video cassette recorder, electronicinstrumentation for the vehicle, navigational systems, or combinationsof these.

In this first preferred embodiment, then, source 40 may be a collectionof signal sources from which a desired visual program may be selected,through some means 43 such as a switch. Program source 40 will alsopresent audio signals to a speaker 44 through cable 46. Speaker 44 maybe placed in any convenient position within the automobile, but is shownplaced in dashboard 32 for convenience. Dashboard 32 also contains videodisplay source 38.

Referring now to FIG. 2 of the drawings, where features common withthose on FIG. 1 are given the same numerals, a second preferredembodiment of the present invention may be appreciated. In thispreferred embodiment the image may be produced by projection device 50having a projection lens 52 which casts an image in the form of adiverging wavefront toward optical element 54. As was shown in FIG. 1,the image of the view ahead is presented to the eyes 22 of the operator.The image passes through windshield 14 and is substantially collimated.A portion of the outside view may pass through optical element 54,necessitating that optical element 54 be capable of transmitting such aview. One means of accomplishing this task is to produce optical element54 as a holographic optical element.

Optical element 54 also presents a collimated image 34 to the eyes 22 ofthe operator. Therefore, optical element 54 must be capable oftransforming the diverging image 56 to the collimated image 34. Programsource 40 can be any of a number of audio-visual sources, such asbroadcast television or video cassette recorded images. The video imageproduced by source 40 is carried to projector 50 by means of a cable 42.Likewise source 40 can produce an audio signal which is presented tospeakers 38, here shown in the roof, but locatable any convenient placewithin the automobile, by line 46.

Both embodiments, shown in FIG. 1 and FIG. 2, present images, focused atinfinity, and located slightly above the line of sight toward developingtraffic conditions in front of the vehicle. The production of theseimages is intended to maintain driver alertness while driving undertedious or boring conditions.

It is not necessary that the display of either preferred embodimentutilize any more than a small fraction of total windshield area, whilemaintaining its ability to display all of the information contained in atelevision picture. The human brain has learned to compensate for thevariety of sizes of television screens. This fact is attested to by thepopularity of miniaturized television sets having one-inch screens. Thisadaptability is explained by an effect which psychologists term "sizeconstancy."

Size constancy explains why the perceived size of the moon is greaterwhen it is near the horizon than when it is higher in the sky, eventhough its size is actually unchanged. There are two theories to explainthis effect: either the human brain (1) perceives the sky above to becloser than the horizon and, in compensating for this perceiveddifference, sees the moon to be bigger then it really should or thebrain (2) estimates the size of the moon based on the emptiness of thesurrounding areas, so that the existence of other features on thehorizon causes the moon to appear bigger. Because the human brain whichhas experienced artificial visual presentation of images has becomeaccustomed to this method of presenting information, it can, to a largedegree, compensate for the actual image shown by the head-up display.

The intensity of the displayed image can be varied, either manually orautomatically, so as to maintain an optimal relative contrast of thedisplayed image to the iamge of the view ahead.

The visual display can take the form of a combiner, thereby allowingimages from both the audio/visual program and the outside world to beoverlaid in the same apparent direction.

If the means for stimulating the evoked responses exemplified by theP300 wave can be shifted to a visual display system, the driving habitsof the vehicle operator may be substantially mollified.

It has been the experience of the applicant that operating a vehicleequipped with a visual display such as the subject of this applicationin fact promotes highway safety by maintaining the driver in aheightened state of awareness while simultaneously performing theprimary function of operating the motor vehicle.

While an appreciation of the present invention may be acquired throughillustration of the two embodiments just described in detail, thesedisclosures are not intended to serve as limitations in any way. Thefull scope of the present invention may be appreciated by one skilled inthe art. This application is intended to cover all such embodiments,whose scope is defined by the following claims.

What is claimed is:
 1. An apparatus for use in a ground vehicle having awindshield through which a driver may view conditions in the directionof travel of the ground vehicle, the apparatus comprising:a first signalsource for generating a first video signal comprising a series of movingvisual images constituting a visual program of unpredictable, newinformation unrelated to the operation of the ground vehicle; a secondsignal source for generating a second video signal comprising an imageof information related to the operation of the ground vehicle; a switchdevice connected to said first and second signal sources for selectingeither said first signal source or said second signal source; and avisual display means connected to said switch device for presenting avisual display of said video signal of said signal source selected bysaid switch device, the visual display utilizing a small fraction of thetotal windshield area and disposed in a position slightly above the lineof sight of the driver toward the direction of travel of the groundvehicle, whereby the driver can observe said visual displaycorresponding to said selected signal source while operating the groundvehicle and such observation will maintain the field of view of thedriver in the proper position for operation of the ground vehicle andwill maintain the driver in a mental state of vigilance.
 2. Theapparatus a claimed in claim 1, wherein said image of informationrelated to the operation of the ground vehicle of said second signalsource constitutes an image of instrument readings for the groundvehicle.
 3. The apparatus as claimed in claim 1, wherein said image ofinformation related to the operation of the ground vehicle of saidsecond signal source constitutes an image of navigational informationfor the ground vehicle.
 4. An apparatus for use in a ground vehiclehaving a windshield through which a driver may view conditions in thedirection of travel of the ground vehicle, the apparatus comprising:afirst signal source for generating a first video signal comprising aseries of moving visual images constituting a visual program ofunpredictable, new information unrelated to the operation of the groundvehicle and a corresponding audio signal constituting an audio programrelated to said visual program; a second signal source for generating asecond video signal comprising an image of information related to theoperation of the ground vehicle; a switch device connected to said firstand second signal sources for selecting either said first signal sourceor said second signal source; a visual display means connected to saidswitch device for presenting a visual display of said video signal ofsaid signal source selected by said switch device, the visual displayutilizing s small fraction of the total windshield area and disposed ina position slightly above the line of sight of the driver toward thedirection of travel of the ground vehicle; and a speaker connected tosaid switch device for reproducing said audio program when said firstsignal source is selected, whereby the driver can observe said visualdisplay corresponding to said selected signal source and hear said audioprogram when said first signal source is selected while operating theground vehicle and such observation will maintain the field of view ofthe driver in the proper position for operation of the ground vehicleand will maintain the driver in a mental state of vigilance.
 5. Theapparatus as claimed in claim 4, wherein said image of informationrelated to the operation of the ground vehicle of said second signalsource constitutes an image of instrument readings for the groundvehicle.
 6. The apparatus as claimed in claim 4, wherein said image ofinformation related to the operation of the ground vehicle of saidsecond signal source constitutes an image of navigational informationfor the ground vehicle.